Deposition methods and apparatuses providing surface activation

ABSTRACT

A deposition method includes, at a first temperature, contacting a substrate with a surface activation agent and adsorbing a first layer over the substrate. At a second temperature greater than the first temperature, the first layer may be contacted with a first precursor, chemisorbing a second layer at least one monolayer thick over the substrate. The first layer may enhance a chemisorption rate of the first precursor compared to the substrate without the surface activation agent adsorbed thereon. One deposition apparatus includes a deposition chamber with a precursor gas dispenser in a contacting zone and a cooling gas dispenser in a cooling zone. A substrate chuck moves by linear translational motion from the contacting zone to the cooling zone. The substrate chuck includes a substrate lift that positions a deposition substrate at an elevation above a heated surface of the substrate chuck when dispensing a cooling gas or surface activation agent. Another deposition apparatus includes a cooling chamber with a cooled substrate chuck and a contacting chamber with a heated substrate chuck. The contacting chamber also has a precursor gas dispenser and the heated substrate chuck includes a substrate lift. A robotic substrate handler moves a substrate from the cooled substrate chuck to the heated substrate chuck.

TECHNICAL FIELD

[0001] This invention relates to deposition methods including surfaceactivation of a substrate and deposition apparatuses providing surfaceactivation of a substrate.

BACKGROUND OF THE INVENTION

[0002] Atomic layer deposition (ALD) is recognized as a depositiontechnique that forms high quality materials with minimal defects andtight statistical process control. Even so, it is equally recognizedthat ALD can have limited application. In some circumstances, thetheoretically expected quality of an ALD layer is not achieved.

[0003] It can be seen that a need exists for an ALD method that forms alayer without introducing intolerable defects into the material.

SUMMARY OF THE INVENTION

[0004] According to one aspect of the invention, a deposition methodincludes, at a first temperature, contacting a substrate with a surfaceactivation agent and adsorbing a first layer over the substrate. At asecond temperature greater than the first temperature, the first layermay be contacted with a first precursor and a second layer may bechemisorbed at least one monolayer thick over the substrate. As anexample, the first layer may enhance a chemisorption rate of the firstprecursor compared to the substrate without the surface activation agentadsorbed thereon. Also, the first temperature may be less than achemisorption temperature of the surface activation agent on thesubstrate. The first and second temperatures may be those of at least aportion of the substrate, those of an outermost surface of thesubstrate, or, respectively, those of the surface activation agent andfirst precursor. The second layer may be chemisorbed on the first layer,or the method may include substantially displacing the first layer fromover the substrate during chemisorption of the first layer on thesubstrate.

[0005] In another aspect of the invention, a deposition method includes,at an initial temperature less than a chemisorption temperature of asurface activation agent, adsorbing the agent over a substrate. At adeposition temperature greater than the initial temperature, a firstspecies may be atomic layer deposited over the substrate. As an example,the surface activation agent may enhance an atomic layer deposition rateof the first species compared to the substrate without the surfaceactivation agent adsorbed thereon. The method may further include atomiclayer depositing a second species on the atomic layer deposited firstspecies, the deposited first and second species combined comprising adeposition material.

[0006] In a further aspect of the invention, a deposition methodincludes adsorbing a surface activation agent over a substrate, at leastan outer surface of the substrate being at a first temperature less thana chemisorption temperature of the agent. A temperature of at least aportion of the substrate may then be altered. A monolayer of a firstcompound may be chemisorbed over the substrate, at least an outersurface of the substrate being at a second temperature greater than thefirst temperature. The agent may be substantially displaced from overthe substrate and a monolayer of a second compound may be chemisorbed onthe first compound monolayer.

[0007] A still further aspect of the invention includes a depositionmethod of contacting a bulk semiconductor wafer with a cooling medium toestablish at least an outer surface of the wafer at an initialtemperature. The wafer may be contacted with a surface activation agent,adsorbing a first layer on the wafer. The initial temperature may beless than a chemisorption temperature of the agent. The wafer may beplaced on a heated wafer chuck, establishing at least an outer surfaceof the wafer at a deposition temperature greater than the initialtemperature. The first layer may be contacted with a depositionprecursor, chemisorbing a second layer at least one monolayer thick overthe wafer. Examples of contacting with a cooling medium includeelevating the wafer over the heated wafer chuck and contacting the waferwith cooling gases as well as placing the wafer on a cooled wafer chuckdifferent from the heated wafer chuck.

[0008] Other aspects of the invention include deposition apparatuses.One such apparatus includes a deposition chamber having at least oneprecursor gas dispenser in each of at least one contacting zone and atleast one cooling gas dispenser in each of at least one cooling zone. Asubstrate chuck moves by linear translational motion from the at leastone contacting zone to the at least one cooling zone. The substratechuck includes a substrate lift that positions a deposition substrate atan elevation above the heated surface of the substrate chuck whendispensing a cooling gas in the at least one cooling zone and whendispensing a surface activation agent in the at least one contactingzone. An exemplary deposition chamber has two contacting zones and onecooling zone. The substrate chuck moves from one contacting zone throughthe cooling zone to another contacting zone. Contacting and coolingzones may be established with at least one of an inert gas curtain orsuitable gas flow conditions. Also, the substrate lift may comprisepositioning pins of a substrate chuck.

[0009] Another deposition apparatus includes at least one coolingchamber having a cooled substrate chuck and at least one contactingchamber having a heated substrate chuck. The contacting chamber may alsohave at least one precursor gas dispenser. The heated substrate chuckmay include a substrate lift that positions a deposition substrate at anelevation above a heated surface of the heated substrate chuck whendispensing a surface activation agent in the contacting chamber. Arobotic substrate handler may move a substrate from the at least onecooled substrate chuck to the at least one heated substrate chuck.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Preferred embodiments of the invention are described below withreference to the following accompanying drawings.

[0011] FIGS. 1-4 are line charts respectively showing the timing forcontacting a substrate in an atomic layer deposition process with asurface activation agent, precursor 1, precursor 2, and purge gas.

[0012]FIG. 5 is a line chart showing the timing for altering temperatureduring the contacting described in FIGS. 1-4.

[0013]FIG. 6 shows a diagrammatic view of a deposition apparatusaccording to one aspect of the invention at a processing step accordingto another aspect of the present invention.

[0014]FIG. 7 shows the deposition apparatus of FIG. 6 at a processingstep subsequent to that shown in FIG. 6.

[0015]FIG. 8 shows a diagrammatic view of an alternative depositionapparatus according to a further aspect of the invention at a processingstep according to yet another aspect of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] This disclosure of the invention is submitted in furtherance ofthe constitutional purposes of the U.S. Patent Laws “to promote theprogress of science and useful arts” (Article 1, Section 8).

[0017] Atomic layer deposition (ALD) involves formation of successiveatomic layers on a substrate. Such layers may comprise an epitaxial,polycrystalline, amorphous, etc. material. ALD may also be referred toas atomic layer epitaxy, atomic layer processing, etc. Further, theinvention may encompass other deposition methods not traditionallyreferred to as ALD, for example, chemical vapor deposition (CVD), butnevertheless including the method steps described herein. The depositionmethods herein may be described in the context of formation on asemiconductor wafer. However, the invention encompasses deposition on avariety of substrates besides semiconductor substrates.

[0018] In the context of this document, the term “semiconductorsubstrate” or “semiconductive substrate” is defined to mean anyconstruction comprising semiconductive material, including, but notlimited to, bulk semiconductive materials such as a semiconductive wafer(either alone or in assemblies comprising other materials thereon), andsemiconductive material layers (either alone or in assemblies comprisingother materials). The term “substrate” refers to any supportingstructure, including, but not limited to, the semiconductive substratesdescribed above.

[0019] Described in summary, ALD includes exposing an initial substrateto a first chemical species to accomplish chemisorption of the speciesonto the substrate. Theoretically, the chemisorption forms a monolayerthat is uniformly one atom or molecule thick on the entire exposedinitial substrate. In other words, a saturated monolayer. Practically,as further described below, chemisorption might not occur on allportions of the substrate. Nevertheless, such an imperfect monolayer isstill a monolayer in the context of this document. In many applications,merely a substantially saturated monolayer may be suitable. Asubstantially saturated monolayer is one that will still yield adeposited layer exhibitin the quality and/or properties desired for suchlayer.

[0020] The first species is purged from over the substrate and a secondchemical species is provided to chemisorb onto the first monolayer ofthe first species. The second species is then purged and the steps arerepeated with exposure of the second species monolayer to the firstspecies. In some cases, the two monolayers may be of the same species.Also, a third species or more may be successively chemisorbed and purgedjust as described for the first and second species.

[0021] Purging may involve a variety of techniques including, but notlimited to, contacting the substrate and/or monolayer with a carrier gasand/or lowering pressure to below the deposition pressure to reduce theconcentration of a species contacting the substrate and/or chemisorbedspecies. Examples of carrier gases include N₂, Ar, He, Ne, Kr, Xe, etc.

[0022] Purging may instead include contacting the substrate and/ormonolayer with any substance that allows chemisorption byproducts todesorb and reduces the concentration of a contacting species preparatoryto introducing another species. A suitable amount of purging can bedetermined experimentally as known to those skilled in the art. Purgingtime may be successively reduced to a purge time that yields an increasein film growth rate. The increase in film growth rate might be anindication of a change to a non-ALD process regime and may be used toestablish a purge time limit.

[0023] ALD is often described as a self-limiting process, in that afinite number of sites exist on a substrate to which the first speciesmay form chemical bonds. The second species might only bond to the firstspecies and thus may also be self-limiting. Once all of the finitenumber of sites on a substrate are bonded with a first species, thefirst species will often not bond to other of the first species alreadybonded with the substrate. However, process conditions can be varied inALD to promote such bonding and render ALD not self-limiting.Accordingly, ALD may also encompass a species forming other than onemonolayer at a time by stacking of a species, forming a layer more thanone atom or molecule thick. The various aspects of the present inventiondescribed herein are applicable to any circumstance where ALD may bedesired. A few examples of materials that may be deposited by ALDinclude silicon nitride, zirconium oxide, tantalum oxide, aluminumoxide, and others.

[0024] Often, traditional ALD occurs within an often-used range oftemperature and pressure and according to established purging criteriato achieve the desired formation of an overall ALD layer one monolayerat a time. Even so, ALD conditions can vary greatly depending on theparticular precursors, layer composition, deposition equipment, andother factors according to criteria known by those skilled in the art.Maintaining the traditional conditions of temperature, pressure, andpurging minimizes unwanted reactions that may impact monolayer formationand quality of the resulting overall ALD layer. Accordingly, operatingoutside the traditional temperature and pressure ranges may riskformation of defective monolayers.

[0025] The general technology of chemical vapor deposition (CVD)includes a variety of more specific processes, including, but notlimited to, plasma enhanced CVD and others. CVD is commonly used to formnon-selectively a complete, deposited material on a substrate. Onecharacteristic of CVD is the simultaneous presence of multiple speciesin the deposition chamber that react to form the deposited material.Such condition is contrasted with the purging criteria for traditionalALD wherein a substrate is contacted with a single deposition speciesthat chemisorbs to a substrate or previously deposited species. An ALDprocess regime may provide a simultaneously contacted plurality ofspecies of a type or under conditions such that ALD chemisorption,rather than CVD reaction occurs. Instead of reacting together, thespecies may chemisorb to a substrate or previously deposited species,providing a surface onto which subsequent species may next chemisorb toform a complete layer of desired material.

[0026] Under most CVD conditions, deposition occurs largely independentof the composition or surface properties of an underlying substrate. Bycontrast, chemisorption rate in ALD might be influenced by thecomposition, crystalline structure, and other properties of a substrateor chemisorbed species. Other process conditions, for example, pressureand temperature, may also influence chemisorption rate. Accordingly,observation indicates that chemisorption might not occur appreciably onportions of a substrate though it occurs at a suitable rate on otherportions of the same substrate. Such a condition may introduceintolerable defects into a deposited material.

[0027] According to one aspect of the invention, a deposition method mayinclude, at a first temperature, contacting a substrate with a surfaceactivation agent and adsorbing a first layer over the substrate. At asecond temperature greater than the first temperature, the first layermay be contacted with a first precursor. A second layer may bechemisorbed at least one monolayer thick over the substrate.Advantageously, the first layer may enhance a chemisorption rate of thefirst precursor compared to the substrate without the surface activationagent adsorbed thereon. Enhancement of a chemisorption rate of the firstprecursor may occur in a variety of ways. For example, wherechemisorption of the first precursor does not occur uniformly across thesubstrate, the surface activation agent may provide chemisorption atsubstantially the same rate, but uniformly across the substrate. Also, asurface activation agent may increase chemisorption rate over regions ofa substrate where chemisorption normally would occur, but at a slowerrate. The observed effect of either enhancement will be to increase theaverage chemisorption rate over all of the substrate.

[0028] Within the context of this document, “adsorption” refers tosurface retention of solid, liquid, or gas molecules, atoms, or ions bya solid or liquid, as opposed to “absorption,” the penetration ofsubstances into the bulk of the solid or liquid. Further, in the contextof this document, chemisorption refers to a type of adsorption in whichchemical bonds are formed between solid, liquid, or gas molecules,atoms, or ions and a solid or liquid surface. The chemical bonds may beweak chemical bonds.

[0029] It is a disadvantage of some deposition methods, for example ALD,that nonuniform deposition may occur over regions of a substrate wheresome difference in surface properties or composition exists in thesubstrate. By adsorbing a first layer including a surface activationagent over a substrate at a first temperature less than a chemisorptiontemperature of the surface activation agent on the substrate, moreuniform formation of the first layer may be established. The secondlayer including the first precursor may be chemisorbed on the firstlayer. Alternatively, the method may include substantially displacingthe first layer from over the substrate during the chemisorbing secondlayer. In such a circumstance, the second layer may be chemisorbed onthe substrate. In substantially displacing the surface activation agent,a negligible amount of surface activation agent may remain on which thefirst precursor may or may not chemisorb. However, substantiallydisplacing the surface activation agent is sufficient to establish adeposited material having the desired properties. Adsorbing the firstlayer, but not chemisorbing the first layer, may provide a more uniformlayer of a surface activation agent than would be established inchemisorption of the same agent or material.

[0030] A variety of surface activation means may be utilized, forexample, the surface activation agent may be the same as the firstprecursor or the surface activation agent may be different from anyother precursors used in a deposition method. For example, andpreferably, the surface activation agent may be a metal halide, a metalorganic, an alcohol, a carboxylic acid, or an amine. Also for example,and more preferably, the surface activation agent may be at least one ofTiCl₄, WF₆, hexamethyldisilazane tetrakis(dimethylamido)titanium,tetraethylorthosilicate, H₂O, methanol, ethanol, isopropanol, formicacid, acetic acid, oxalic acid, NH₃, methylamine, ethylamine, ordimethylamine. Contacting of the substrate may comprise contacting abulk semiconductor wafer, or some other material formed over such awafer, wherein such contacting initiates formation of a new material.Alternatively, contacting a substrate may include contacting apreviously chemisorbed layer of a deposition precursor and adsorbing thesurface activation agent on the previously chemisorbed layer. That is,adsorbing a surface activation agent may be advantageous both ininitiating a deposition method as well as continuing a deposition methodafter initiation.

[0031] A variety of processing conditions may also be suitable accordingto various aspects of the invention. For example, at a firsttemperature, when contacting a substrate with a surface activation agentand, at a second temperature, contacting the surface activation agentwith a first precursor, the first and second temperatures may be thoseof at least a portion of the substrate. Also, the first and secondtemperatures may be those of an outermost surface of the substrate.Still further, the first and second temperatures may be, respectively,those of the surface activation agent and the first precursor. Actualfirst and second temperatures will depend largely on the individualproperties of the surface activation agent and the first precursor aswell as a desired deposition material.

[0032] Also, chemisorbing the second layer may be accomplished in avariety of ways. The first precursor may consist essentially of a singleprecursor species. Alternatively, as discussed above, a plurality ofspecies may be used as the first precursor. The second layer chemisorbedfrom the first precursor may consist essentially of a monolayer.Further, the method may include contacting the second layer with asecond precursor and chemisorbing at least one monolayer thick on thesecond layer. A chemisorption product of the first and second precursorsmay form a deposition material. The chemisorption product may consistessentially of a monolayer of the deposition material.

[0033] As another aspect of the invention, a deposition method mayinclude, at an initial temperature less than a chemisorption temperatureof a surface activation agent, adsorbing the agent over a substrate. Ata deposition temperature greater than the initial temperature, a firstspecies may be atomic layer deposited over the substrate. Similarsurface activation agents to those described above may be used. Such asurface activation agent may enhance an atomic layer deposition rate ofthe first species compared to the substrate without the surfaceactivation agent adsorbed thereon. The initial and depositiontemperatures may be those of at least a portion of the substrate, aswell as other substances, such as those described above. The method mayfurther include atomic layer depositing a second species on the atomiclayer deposited first species. The deposited first and second speciescombined may comprise a deposition material.

[0034] As a further aspect of the invention, a deposition method mayinclude adsorbing a surface activation agent over a substrate. At leastan outer surface of the substrate may be at a first temperature lessthan a chemisorption temperature of the agent. A temperature of at leasta portion of the substrate may then be altered and a monolayer of afirst compound may be chemisorbed over the substrate. At least an outersurface of the substrate may be at a second temperature greater than thefirst temperature. The chemisorption may substantially displace theagent from over the substrate. The method may further includechemisorbing a monolayer of a second compound on the first compoundmonolayer. As before, the adsorbed surface activation agent mayadvantageously enhance a chemisorption rate of the first compoundcompared to the substrate without the surface activation agent adsorbedthereon.

[0035] A still further aspect of the invention provides a depositionmethod that includes contacting a bulk semiconductor wafer with acooling medium to establish at least an outer surface of the wafer at aninitial temperature. The wafer may be contacted with a surfaceactivation agent, adsorbing a first layer on the wafer. The initialtemperature may be less than a chemisorption temperature of the agent.The wafer may be placed on a heated wafer chuck and at least an outersurface of the wafer established at a deposition temperature greaterthan the initial temperature. The first layer may be contacted with adeposition precursor, chemisorbing a second layer at least one monolayerthick over the wafer. In keeping with the previous description, thefirst layer may enhance a chemisorption rate of the deposition precursorcompared to the wafer without the surface activation agent adsorbedthereon. Also, the surface activation agent may be the same as thedeposition precursor or, alternatively, different.

[0036] Contacting with the cooling medium may be accomplished in avariety of ways. As one example, the wafer may be elevated over theheated wafer chuck and contacted with cooling gases. Placing the waferon the heated wafer chuck may include lowering the wafer from theposition where the wafer was contacted with cooling gases. Also, forexample, contacting the wafer with a cooling medium may include placingthe wafer on a cooled wafer chuck different from the heated wafer chuck.

[0037] Contacting the wafer with a surface activation agent anddeposition precursor may also be accomplished in a variety of ways. Forexample, the wafer may be moved within a single chamber of a depositionapparatus from a first zone containing a surface activation agent to asecond zone containing the deposition precursor. The moving may beaccomplished by linear translational motion of the heated wafer chuck.Also for example, the wafer may be moved from a cooled wafer chuck in afirst chamber of a multiple chamber deposition apparatus to a secondchamber of the apparatus wherein contacting with the agent andcontacting with the precursor may occur. The moving may be accomplishedby a robotic wafer handler.

[0038] Accordingly, other aspects of the invention include depositionapparatuses that accomplish surface activation of a substrate. Oneexemplary deposition apparatus includes a deposition chamber having atleast one precursor gas dispenser in each of at least one contactingzone and at least one cooling gas dispenser in each of at least onecooling zone. A substrate chuck moves by linear translational motionfrom the at least one contacting zone to the at least one cooling zone.The substrate chuck may include a substrate lift that positions adeposition substrate at an elevation above a heated surface of thesubstrate chuck. Such positioning of a deposition substrate may occurwhen dispensing a cooling gas in the at least one cooling zone and whendispensing a surface activation agent in the at least one contactingzone.

[0039]FIGS. 6 and 7 show a deposition apparatus 2 with a depositionchamber 4 having a contacting zone 20 and a contacting zone 24 as wellas a cooling zone 22. Precursor gas dispenser 6 supplies gases 6 aand/or 6 b to contacting zone 20. Precursor gas dispenser 10 suppliesgases 10 a and/or 10 b to contacting zone 24. Cooling gas dispenser 8supplies gas 8 a to cooling zone 22. Zone boundaries 18 isolatecontacting zone 20 from cooling zone 22 and contacting zone 24 fromcooling zone 22.

[0040] Isolation of zones 20, 22, and 24 within deposition chamber 4 maybe accomplished in a variety of ways. As one example, contacting andcooling zones may be established with an inert gas curtain as known tothose skilled in the art. Nitrogen, Ar, and He are examples of suitableinert gases. Also, such zones may be established using suitable gas flowconditions as known to those skilled in the art. For example, laminarflow conditions may be suitable. The suitability of particularconditions may be experimentally determined in any manner known to thoseskilled in the art for a particular deposition chamber and combinationof gases and apparatuses inside the chamber that can affect gas mixing.The gas flow conditions may minimize mixing of flowing gases incontacting and cooling zones such that only negligible mixing occurs ofsupplied gases in a region defined as a zone boundary, for example, zoneboundaries 18. Further, the cooling zone may consist essentially of aninert gas curtain isolating two contacting zones. For example, gas 8 amay be a cooling gas as well as an inert gas such that no separate inertgas curtain is desired to isolate contacting zone 20 from cooling zone22 and contacting zone 24 from cooling zone 22.

[0041]FIG. 6 also shows a wafer chuck 12 having positioning pins 14 as asubstrate lift upon which wafer 16 is placed. Positioning pins 14position wafer 16 at an elevation above wafer chuck 12. Accordingly,when wafer chuck 12 is heated, wafer 16 will be distanced from a heatedsurface of wafer chuck 12 for cooling of at least an outer surface ofwafer 16 by gas 8 a.

[0042] As shown in FIG. 7, wafer chuck 12 may move by lineartranslational motion from cooling zone 22 to contacting zone 20 andpositioning pins 14 may lower wafer 16 from the elevation above theheated surface of wafer chuck 12. FIG. 7 shows wafer 16 completelylowered so as to rest on wafer chuck 12, however, an intermediateposition between the positions shown in FIGS. 6 and 7 may also besuitable. Gases 6 a and/or 6 b may be dispensed from precursor gasdispenser 6 with wafer 16 in a lowered position to accomplishchemisorption of a deposition precursor on wafer 16. Although not shown,wafer chuck 12 may also move into contacting zone 24 without loweringpositioning pins 14 to accomplish adsorption of a surface activationagent dispensed from precursor gas dispenser 10 at the temperatureestablished in cooling zone 22. Accordingly, substrate chuck 12 may movefrom one contacting zone through cooling zone 22 to another contactingzone in performing a deposition method such as the various methodsdescribed herein. Temperature, contacting of surface activation agentsand precursors, chemisorption, and adsorption may be controlled aspreferred accordingly to the various aspects of the invention using theapparatus of FIGS. 6 and 7.

[0043] Similarly, such methods may also be practiced in a depositionapparatus that includes at least one cooling chamber having a cooledsubstrate chuck and at least one contacting chamber having at least oneprecursor gas dispenser. The at least one contacting chamber may alsohave a heated substrate chuck including a substrate lift that positionsa deposition substrate at an elevation above a heated surface of theheated substrate chuck when dispensing a surface activation agent in thecontacting chamber. A robotic substrate handler may be provided thatmoves a substrate from the at least one cooled substrate chuck to the atleast one heated substrate chuck. One example of such an apparatus isshown in FIG. 8.

[0044] Deposition apparatus 30 of FIG. 8 includes a contacting chamber40 and a cooling chamber 42. A heated wafer chuck 32 provided incontacting chamber 40 includes positioning pins 34 analogous topositioning pins 14 shown in FIGS. 6 and 7. Positioning pins 34 areshown in FIG. 8 in a raised position. A gas dispenser 38 supplies gases38 a and/or 38 b to contacting chamber 40. Cooling chamber 42 includes acooled wafer chuck 36. Although not shown, a robotic wafer handler moveswafer 16 from cooled wafer chuck 36 to heated wafer chuck 32.

[0045] When adsorbing a surface activation agent on wafer 16,positioning pins 34 may operate as a substrate lift to elevate wafer 16above the heated surface of the substrate chuck. Accordingly, adsorptionat a temperature lower than that of heated wafer chuck 32 may beaccomplished. Positioning pins 34 may then lower wafer 16 from theelevation above the heated surface to increase temperature andaccomplish chemisorption of a deposition precursor in contacting chamber40. Accordingly, both a surface activation agent and a depositionprecursor may be supplied from gas dispenser 38 at appropriate times toaccomplish adsorption and chemisorption.

[0046] Turning to FIGS. 1-5, a process regime is described for ALD thatis within the scope of the present invention. FIGS. 1-4 show the cycliccontacting and purging of a substrate with surface activation agent(SAA), Precursor 1 (P1), and Precursor 2 (P2). As shown in FIG. 1, asubstrate is first contacted with SAA from Time 0 (TO) to Time 1 (T1).An optional purge of SAA that is not adsorbed to a substrate may thenoccur from T1 to T2. Such purge is optional depending on the particularSAA and P1 selected. For example, if SAA and P1 are identical, then itis conceivable that purging might not occur prior to chemisorption ofP1. Adsorbed SAA is then contacted with P1 from T2 to T3, chemisorbingP1 over the substrate. As discussed above, P1 may chemisorb either toadsorbed SAA, to the substrate after displacing SAA, or both. Afterpurging excess P1 from T3 to T4, chemisorbed P1 is contacted with P2from T4 to T5. After purging excess P2 from T5 to T6, the cycle beginsagain. However, the cycle may begin by either contacting chemisorbed P2with SAA or P1 from T6 to T7. As also discussed above, it may bedesirable only to adsorb SAA as an initial layer or to adsorb SAA at thebeginning of more than one cycle of chemisorbing deposition precursors.Accordingly, contacting SAA from T6 to T7 is shown in dashed outline asan optional step and contacting with P1 from T6 to T7 is shown indash-dot outline also indicating an optional step.

[0047] The cycle from T0 to T5 thus may form at least a monolayer of achemisorption product of P1 and P2. The purge from T5 to T6 prepares thechemisorption product of P1 and P2 to begin a new cycle at T6. Notably,the time intervals from T0 to T1 to T2, etc., are shown as equal merelyfor graphical convenience. In practice, such times may be individuallydetermined according to the knowledge of those skilled in the artconsidering the aspects and advantages of the inventions describedherein.

[0048]FIG. 5 shows altering the temperature, preferably substratetemperature, as part of the described method. Temperature 1 (Temp1) ismaintained from T0 to T1 during contacting of SAA. Thereafter,temperature is increased to Temp2 during purging from T1 to T2 andmaintained at Temp2 during contacting of P1, purging, and contacting ofP2 from T2 to T5. Depending on whether SAA or P1 will be contacted fromT6 to T7, temperature may be reduced from Temp2 to Temp1 from T5 to T6or may remain at Temp2. Accordingly, temperature remaining at Temp2 fromT5 to T7 is shown in dash-dot outline to correspond with contacting P1and decreasing temperature is shown in dashed outline to correspond withcontacting SAA.

[0049] In keeping with the various aspects of the invention, otherscenarios of contacting surface activating agents and precursors andaltering temperatures are also conceivable, some of which are expresslydescribed herein. For example, since temperature changes are involved,it is conceivable that a desired temperature might not be establishedbefore starting contacting of a surface activation agent or precursor.Rather, it may be suitable to establish such temperature some time afterthe start of contacting. Consideration may be made regarding whether thedelay in establishing a temperature is justified by an improvement inadsorption or chemisorption efficiency. That is, if a desiredtemperature for chemisorption is established before contacting, then adifference in chemisorption efficiency might exist compared to notestablishing the temperature until after contacting begins. Accordingly,a deposition method according to the various aspects of the inventionherein may be optimized for processing time and efficiency depending onthe priorities and objectives of a particular process.

[0050] In compliance with the statute, the invention has been describedin language more or less specific as to structural and methodicalfeatures. It is to be understood, however, that the invention is notlimited to the specific features shown and described, since the meansherein disclosed comprise preferred forms of putting the invention intoeffect. The invention is, therefore, claimed in any of its forms ormodifications within the proper scope of the appended claimsappropriately interpreted in accordance with the doctrine ofequivalents.

1. A deposition method comprising: at a first temperature, contacting asubstrate with a surface activation agent and adsorbing a first layerover the substrate; and at a second temperature greater than the firsttemperature, contacting the first layer with a first precursor andchemisorbing a second layer at least one monolayer thick over thesubstrate.
 2. The deposition method of claim 1 wherein the first layerenhances a chemisorption rate of the first precursor compared to thesubstrate without the surface activation agent adsorbed thereon.
 3. Thedeposition method of claim 1 wherein the surface activation agentcomprises a metal halide, metal organic, alcohol, carboxylic acid, oramine.
 4. The deposition method of claim 1 wherein the surfaceactivation agent comprises at least one of TiCl₄, WF₆,hexamethyldisilazane, tetrakis(dimethylamido)titanium,tetraethylorthosilicate, H₂O, methanol, ethanol, isopropanol, formicacid, acetic acid, oxalic acid, NH₃, methylamine, ethylamine, ordimethylamine.
 5. The deposition method of claim 1 wherein the firsttemperature is less than a chemisorption temperature of the surfaceactivation agent on the substrate.
 6. The deposition method of claim 1wherein the first and second temperatures are those of at least aportion of the substrate.
 7. The deposition method of claim 1 whereinthe first and second temperatures are those of an outermost surface ofthe substrate.
 8. The deposition method of claim 1 wherein the first andsecond temperatures are respectively those of the surface activationagent and first precursor.
 9. The deposition method of claim 1 whereinthe substrate comprises a bulk semiconductor wafer.
 10. The depositionmethod of claim 1 wherein the second layer is chemisorbed on the firstlayer.
 11. The deposition method of claim 1 wherein the contacting thesubstrate comprises contacting a previously chemisorbed layer of adeposition precursor and adsorbing the surface activation agent on thepreviously chemisorbed layer.
 12. The deposition method of claim 1further comprising substantially displacing the first layer from overthe substrate during the chemisorbing the second layer.
 13. Thedeposition method of claim 1 wherein the surface activation agent is thesame as the first precursor.
 14. The deposition method of claim 1wherein the second layer consists essentially of a monolayer.
 15. Thedeposition method of claim 1 wherein the first precursor consistsessentially of a single precursor species.
 16. The deposition method ofclaim 1 further comprising contacting the second layer with a secondprecursor and chemisorbing a third layer at least one monolayer thick onthe second layer, forming a chemisorption product of the first andsecond precursors comprising a deposition material.
 17. The depositionmethod of claim 16 wherein the chemisorption product consistsessentially of a monolayer of the deposition material.
 18. A depositionmethod comprising: at an initial temperature less than a chemisorptiontemperature of a surface activation agent, adsorbing the agent over asubstrate; and at a deposition temperature greater than the initialtemperature, atomic layer depositing a first species over the substrate.19. The deposition method of claim 18 wherein the surface activationagent enhances an atomic layer deposition rate of the first speciescompared to the substrate without the surface activation agent adsorbedthereon.
 20. The deposition method of claim 18 wherein the surfaceactivation agent comprises a metal halide, metal organic, alcohol,carboxylic acid, or amine.
 21. The deposition method of claim 18 whereinthe surface activation agent comprises at least one of TiCl₄, WF₆,hexamethyldisilazane, tetrakis(dimethylamido)titanium,tetraethylorthosilicate, H₂O, methanol, ethanol, isopropanol, formicacid, acetic acid, oxalic acid, NH₃, methylamine, ethylamine, ordimethylamine.
 22. The deposition method of claim 18 wherein the surfaceactivation agent is the same as the first species.
 23. The depositionmethod of claim 18 wherein the initial and deposition temperatures arethose of at least a portion of the substrate.
 24. The deposition methodof claim 18 further comprising substantially displacing the surfaceactivation agent from over the substrate during the atomic layerdepositing the first species.
 25. The deposition method of claim 18further comprising atomic layer depositing a second species on theatomic layer deposited first species, the deposited first and secondspecies combined comprising a deposition material.
 26. A depositionmethod comprising: adsorbing a surface activation agent over asubstrate, at least an outer surface of the substrate being at a firsttemperature less than a chemisorption temperature of the agent; alteringa temperature of at least a portion of the substrate; chemisorbing amonolayer of a first compound over the substrate, at least an outersurface of the substrate being at a second temperature greater than thefirst temperature, and substantially displacing the agent from over thesubstrate; and chemisorbing a monolayer of a second compound on thefirst compound monolayer.
 27. The deposition method of claim 26 whereinthe adsorbed surface activation agent enhances a chemisorption rate ofthe first compound compared to the substrate without the surfaceactivation agent adsorbed thereon.
 28. The deposition method of claim 26wherein the surface activation agent comprises a metal halide, metalorganic, alcohol, carboxylic acid, or amine.
 29. The deposition methodof claim 26 wherein the surface activation agent comprises at least oneof TiCl₄, WF₆, hexamethyldisilazane, tetrakis(dimethylamido)titanium,tetraethylorthosilicate, H₂O, methanol, ethanol, isopropanol, formicacid, acetic acid, oxalic acid, NH₃, methylamine, ethylamine, ordimethylamine.
 30. The deposition method of claim 26 wherein the surfaceactivation agent is the same as the first compound.
 31. A depositionmethod comprising: contacting a bulk semiconductor wafer with a coolingmedium to establish at least an outer surface of the wafer at an initialtemperature; contacting the wafer with a surface activation agent andadsorbing a first layer on the wafer, the initial temperature being lessthan a chemisorption temperature of the agent; placing the wafer on aheated wafer chuck and establishing at least the outer surface of thewafer at a deposition temperature greater than the initial temperature;and contacting the first layer with a deposition precursor andchemisorbing a second layer at least one monolayer thick over the wafer.32. The deposition method of claim 31 wherein the contacting with thecooling medium comprises elevating the wafer over the heated wafer chuckand contacting the wafer with cooling gases and wherein the placing thewafer comprises lowering the wafer onto the heated wafer chuck.
 33. Thedeposition method of claim 31 wherein the contacting with the coolingmedium comprises placing the wafer on a cooled wafer chuck differentfrom the heated wafer chuck.
 34. The deposition method of claim 31wherein the contacting with the surface activation agent and depositionprecursor comprises moving the wafer within a single chamber of adeposition apparatus from a first zone containing the surface activationagent to a second zone containing the deposition precursor.
 35. Thedeposition method of claim 34 wherein the moving is accomplished bylinear translational motion of the heated wafer chuck.
 36. Thedeposition method of claim 31 wherein the contacting with the surfaceactivation agent and deposition precursor comprises moving the waferfrom a cooled wafer chuck in a first chamber of a multiple chamberdeposition apparatus to a second chamber of the apparatus whereincontacting with the agent and contacting with the precursor may occur.37. The deposition method of claim 36 wherein the moving is accomplishedby a robotic wafer handler.
 38. The deposition method of claim 31wherein the first layer enhances a chemisorption rate of the depositionprecursor compared to the wafer without the surface activation agentadsorbed thereon.
 39. The deposition method of claim 31 wherein thesurface activation agent comprises a metal halide, metal organic,alcohol, carboxylic acid, or amine.
 40. The deposition method of claim31 wherein the surface activation agent comprises at least one of TiCl₄,WF₆, hexamethyldisilazane, tetrakis(dimethylamido)titanium,tetraethylorthosilicate, H₂O, methanol, ethanol, isopropanol, formicacid, acetic acid, oxalic acid, NH₃, methylamine, ethylamine, ordimethylamine.
 41. The deposition method of claim 31 wherein the surfaceactivation agent is the same as the deposition precursor.
 42. Thedeposition method of claim 31 wherein the second layer consistsessentially of a monolayer.
 43. The deposition method of claim 31wherein the deposition precursor consists essentially of a singleprecursor species.
 44. A deposition apparatus comprising: a depositionchamber having at least one precursor gas dispenser in each of at leastone contacting zone and at least one cooling gas dispenser in each of atleast one cooling zone; and a substrate chuck that moves by lineartranslational motion from the at least one contacting zone to the atleast one cooling zone, the substrate chuck comprising a substrate liftthat positions a deposition substrate at an elevation above a heatedsurface of the substrate chuck when dispensing a cooling gas in the atleast one cooling zone and when dispensing a surface activation agent inthe at least one contacting zone.
 45. The apparatus of claim 44 whereinthe substrate comprises a bulk semiconductor wafer.
 46. The apparatus ofclaim 44 wherein the deposition chamber has two contacting zones and onecooling zone and the substrate chuck moves from one contacting zonethrough the cooling zone to another contacting zone.
 47. The apparatusof claim 46 wherein the cooling zone consists essentially of an inertgas curtain isolating the two contacting zones.
 48. The apparatus ofclaim 44 wherein the substrate lift lowers a deposition substrate fromthe elevation above the heated surface of the substrate chuck whendispensing precursor gas in the at least one contacting zone.
 49. Theapparatus of claim 44 wherein substrate lift comprises positioning pinsof the substrate chuck.
 50. The apparatus of claim 44 wherein contactingand cooling zones are established with at least one of an inert gascurtain or suitable gas flow conditions.
 51. A deposition apparatuscomprising: at least one cooling chamber having a cooled substratechuck; at least one contacting chamber having at least one precursor gasdispenser and having a heated substrate chuck including a substrate liftthat positions a deposition substrate at an elevation above a heatedsurface of the heated substrate chuck when dispensing a surfaceactivation agent in the contacting chamber; and a robotic substratehandler that moves a substrate from the at least one cooled substratechuck to the at least one heated substrate chuck.
 52. The apparatus ofclaim 51 wherein the substrate comprises a bulk semiconductor wafer. 53.The apparatus of claim 51 wherein the substrate lift lowers a depositionsubstrate from the elevation above the heated surface of the substratechuck when dispensing precursor gas in the at least one contactingchamber.
 54. The apparatus of claim 51 wherein the substrate liftcomprises positioning pins of the heated substrate chuck.